For example, the continuous use of a liquid crystal display device, which displays images using a liquid crystal panel and a backlight, reduces the amount of light of the backlight. Accordingly, the continuous use of the liquid crystal display device over a long period of time prevents the backlight from emitting light with recommended luminance. When such a situation occurs, the backlight or display device itself needs to be replaced. Such replacement requires not small cost and affects the asset management of the user of the display device. For this reason, there has been a demand to predict the life of display devices.
Patent Literature 1 proposes a life prediction system that uses, as a criterion for determining the life of a display device, the time point when the maximum amount of light of a backlight, which emits light through a liquid crystal panel, that is, the maximum luminance will fall below a predetermined critical luminance and calculates the time period over which the maximum luminance will remain within the critical luminance, on the basis of measured luminances of the display device, Lehmann's expression, and the like.